The Tricky Trees were without Morgan Gibbs-White (ankle), Elliot Anderson (foot), Danilo (ankle) and Ibrahim Sangare (hamstring) for the 3-0 loss to Arsenal last weekend, and the former two remain doubtful for the visit of the Tractor Boys.
Santo was also forced into an early change at the Emirates, having to withdraw Anthony Elanga at half time with the Swede in "a lot of pain" due to a shoulder problem, and his availability for Saturday is also up in the air.
The Garibaldi boss may very well call upon Jota Silva to start on the left flank instead, but there is optimism that Gibbs-White - who is being carefully managed after hurting his ankle against Chelsea in October - will be OK to play.
The England international may therefore demote James Ward-Prowse to the bench, and the same is true of Chris Wood, who was only considered for a substitute appearance in North London but is now sure to displace Taiwo Awoniyi.
Ryan Yates and Nicolas Dominguez will link arms in the engine room if Ward-Prowse makes way for Gibbs-White, and Callum Hudson-Odoi - whose 18 chances created are the most of any Forest player in the top flight this term - struts his stuff on the right.
Despite seeing his side concede three goals in back-to-back matches, Santo should stick with the recognisable rearguard of Ola Aina, Murillo, Nikola Milenkovic and Alex Moreno in front of Matz Sels.
Nottingham Forest possible starting lineup:
Sels; Aina, Milenkovic, Murillo, Moreno; Yates, Dominguez; Hudson-Odoi, Gibbs-White, Silva; Wood